Scientists are reporting that they have made a living cell from DNA that was originally synthesized in a lab. This is still a step away from creating a completely synthetic life form. The DNA that the researchers synthesized was copied from a living organism.

But NPR's Joe Palca reports, it is an important, and some say troubling, step on the road to creating life in the laboratory.

JOE PALCA: Many scientists have strong opinions about Craig Venter. But even his detractors will admit, he's a man who thinks big. Venter famously took on the federal government in a race to be the first to sequence the human genome. Now he wants to create life, starting with the four chemical constituents of DNA known as A, T, C and G that make up the genetic code.

Dr. VENTER CRAIG (Scientist): Using those to actually write new chemical software and booting up that software to create new life forms.

PALCA: Venter says there were two enormous hurdles to accomplishing his goals. First, he needed to figure out how to make a very big piece of DNA. Most chemical synthesis techniques stop working when you get to a few thousand letters of DNA.

Dr. VENTER: We wanted to build something close to a million. So, solving all the chemistry has taken much of the last 15 years.

PALCA: Venter and his colleagues eventually solved this problem by putting smaller fragments of DNA they made in the lab into yeast cells and letting the yeast cells stitch the fragments together.

The second hurdle was figuring out how to transfer such a large chunk of DNA into a cell without breaking it.

Dr. VENTER: DNA becomes very brittle in large pieces.

PALCA: Once they solved that, they needed the transplanted DNA to switch on, start running the show inside the cell. That last step turned out to be harder than Venter thought it would be. This is what he told me last June when I was working on a project for the National Academy Keck Futures Initiative.

Dr. VENTER: Until we have a living organism totally derived from that genetic code, we won't have achieved the first synthetic cell.

PALCA: Now, nearly a year later...

Dr. VENTER: We're here today to announce the first synthetic cell.

PALCA: At a news conference, Venter said he had succeeded in putting synthetic DNA into a cell and getting that cell to grow and divide, passing its synthetic genes on from one generation to the next.

Dr. JAMES COLLINS (Synthetic Biologist, Boston University): I don't actually think that this work represents the creation of an artificial life form.

PALCA: James Collins a synthetic biologist at Boston University.

Dr. COLLINS: So the genome is a stitched-together copy of the DNA of an organism that exists in nature.

PALCA: The genome the Venter team started with was from a living cell. Collins says making a precise copy of all that cell's DNA, moving it to a cell from a different species and getting it to start working, it's a marvelous achievement, but it's not creating new life.

Dr. COLLINS: We don't know enough biology to create or synthesize life. I think we're far removed from understanding, how would you build a truly artificial genome from scratch?

PALCA: Even so, Venter's accomplishment is bound to raise questions whether the work is morally acceptable. It's a discussion bioethicists have been having for some time.

Dr. GREGORY KAEBNICK (Scholar, Hastings Center): It's not as though we've suddenly got to the point that particular moral issues are raised here that weren't already present in the field.

PALCA: Gregory Kaebnick is a scholar at the Hastings Center, a bioethics think tank. Kaebnick says there are two basic concerns about what Venter and others in the new field of synthetic biology are doing. First, that one of these synthetic organisms will escape from the lab and run amok. And, second, whether this kind of work crosses a line where humans start playing God.

Dr. KAEBNICK: Up until now, organisms have come into being on their own, as it were. They've evolved on their own.

PALCA: But Kaebnick says Venter's work says that may not longer be the case.

Dr. KAEBNICK: And for some that's a troubling development.

PALCA: But for Craig Venter, that's exactly the point of doing this work in the first place.

Dr. VENTER: We decided that writing new biological software and creating new species, we could create new species to do what we want them to do, not what they evolved to do.

PALCA: Venter has founded a company called Synthetic Genomics, where he intends to use these new species to do things like make new fuels and new vaccines. For the moment, Venter and his colleagues are the only ones with the money and techniques to do this kind of genomic manipulation. But others are working in related areas, and a new world of synthetic microorganisms might not be far off.

NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR’s programming is the audio.